Press for drawing sheet metal



April 1 1, 1933. c J. RHQDES 1,903,475

PROCESS FOR DRAWING SHEET METAL Filed May 24, 1950 I Int/672507: (harks kscyafi Rhodes,

KOVMm B-QW flaw Patented Apr. 11, 1933 UNITED STATES PATENT OFFICE CHARLES JOSEPH RHODES OF WAKEFIELD, ENGLAND j PRESS FOR DRAWING SHEET METAL Application filed May 24, 1930, Serial No. 455,251, and in Great Britain November 4, 1929.

This invention relates to presses for drawing sheet metal, and it refers more particularly to presses in which the block or former of the lower die, instead of being fixed, has imparted to it a reciprocal movement whereby during the drawing operation it is caused to move towards the upper or movable die and away from said die during the return portion of its movement.

' According to the present invention, the movement of the blocker former is effected hydraulically, provision being made whereby the downward movement of the usualpressure table is utilized to compress a liquid, causing same to actuate means whereby the block is raised. The return of the pressure table relieves the pressure operating the block which returns to its normal position.

In practice, according to one form of the invention, there is provided a closed vessel filled with liquid, oil or water, for example, said vessel being secured in any convenient manner below the bed of the machine. Passing in a liquid tight manner throng-lithe 5 closureof said vessel, are pins or plungers,

upon the outer ends of which the pressure table is supported. A draw-ring is supported from said table by pins in the usual manner.

The block is connected to the upper end of a plunger which passesfreely. through the table of the machine and also through the pressure table and into the aforesaid vessel, a suitable gland and stuffing box being provided to prevent'the escape of the liquid at this point.

The plunger is provided at its lower end with a head between the upper surface of which and the inner surface of the closure for the vessel, there is interposed a helical spring which surrounds the body of the plunger.

In order that the invention maybe the better understood, reference is made to the appended drawing, which shows a sectional elevation of an embodiment of the press and in which 1 indicates the table of the press from.

which is suspended by means of bolts 2 a chamber 3 containing a liquid and-having a closure 5 secured to the upper endthereof by means of bolts 6. Extending from this chamher are opposed lugs, with which nuts of'said bolts cooperate, as clearly shown. The cover is provided at 7 with a stufling box 8 and glandr9 through which'passes a downwardly extending rod or plunger 10 having .at'iits lower end a collar or head 11 and surrounding which rod is a helical spring 12, the lower end abutting the upper surface of the col: lar and the upper end of said, spring abut ting the underside of the stufiingbox 8, The rod 10 passes freely through a plate ortablel' 13 from the underside of which project pins or plunger-s14 which pass through stuffing boxes and glands upon the closure or cover 5 into the chamber 3. 15 indicates the fixed die in which is disposed a drawring 16 and a block 17 attached to the upper end of theaforesaid' rod 10, the drawring 16 being supported by pins 18 resting upon the upper surface of the aforesaidtable or'plate 13. o

19 indicates the upper movable die-mountedupon the ram of the press :in the usual manner. Obviously, various modifications may be made in the construction and arrangement of the parts, and if desired, a plurality drawrings may be used, any desired variation in the pressure-exerted upon the liquid by the various plungers being adjusted by suitably selecting the diameters thereof. Provision may be made whereby the initial resistance of the spring 12 may be adjusted, so for example, the end of the plunger 10 maybe screw-threaded and the head 11 threaded to engage said screw thread or other means to the same end, may be provided. V

The depression of the drawring 16 causes the plungers upon the pressure table 13 to be.

forced into the vessel3 compressing the liquid therein, which thereupon acts upon the rod or plunger 10 supportingthe block 17 raising said plunger against the action of spring 12.

, As the pressure upon the draw ring 16 is relaxed the spring acts to force the plunger of the block 17 downwards and the liquid in the vessel 3 acts upon the plungers 14 of drawring 16 raising it into its normal position.

I claim: q

1. In a press for drawing sheet metal, a fixed die, a movable block in saidfixed die, a closed chamber containing a liquid, a plunger connected to the movable block and passing into said chamber, a spring opposing the movement of said plunger in one direction, a drawring, a table supporting said drawring, and plungers passing into said chamber and supporting said table. 7

2. In a press for drawing sheet metal, a fixed die, a movable block in said fixed die, a closed chamber containing a liquid, a plunger connected to the movable block and passing into said chamber, a spring opposing the movement of said plunger in one direction, a plurality of drawrings, tables supporting said drawrings and plungers passing into said chamber and supporting said table.

3. In a press for drawing sheet metal, a fixed die, a movable die, a movable block in said fixed die, a chamber containing liquid, means supporting said chamber below the table of the press, a closure for said chamber, a plunger on said movable block passing 1 through said closure, a head upon said plunger, a spring interposed between said head and said closure, a pressure table, plungers supporting said pressure table and passing through said closure, a drawring and pins supporting said drawring from said pressure table.

4. In a press for'drawi'ng sheet metal, in combination, a fixed die, a movable block in said fixed die, a drawring in said fixed die, a closed chamber, a liquid completely filling said chamber, means associated with the drawring for compressing said liquid, said means, including a ram, which latter carries a die, and means associated with said movable block whereby same is actuated by the compression of the liquid, said latter means including a plunger and a bearing therefor.

5. In a press for drawing sheet metal, in combination, a fixed die, a movable block, in

' said fixed die, a drawring in said fixed die,

a closed chamber, a liquid completely filling said chamber, means associated with the drawring for compressing said liquid, a headed rod rigidly associated with said movable block, the head of said rod being disposed in said liquid for actuation by the compression of said liquid, and means including said liquid for returning said block when the pressure upon the drawring is relaxed.

6,. In a drawing press for sheetmetal, the combination of a table, a closed container disposed below said table and having opposed lugs, a compressible liquid completely filling said container, a die rigid with said table, oppositely movable drawring and block structures associated with said die, individual means rigid with said respective structures and terminally disposed in said liquid, another die for moving one of said structures in one direction whereby, responsive to compression of said liquid, to move the other structure in the opposite direction, and means cooperating with said table and said lugs to rigidly hold said container.

7. In a drawing press for sheet metal, the combination of a table, a closed chamber completely filled with liquid and disposed below said table in spaced relation with the latter, a die fixedly carried on said table, oppositely movable drawring and block structures cooperating with said die, plungers rigid with said drawring and terminally disposed in the liquid, a plunger rigid with said block and also terminally disposed in the liquid, a movable 'die. for urging said drawring in one direction, whereby the liquid may be effective to urge said second plunger with its block in the opposite direction, threaded rods cooperating with said table and said lugs, and nuts carried by said rods and engaging opposite sides of said lugs to rigid-- ly hold said chamber in position.

8. In. a sheet metal press, the combination of a fixed die, a chamber having a liquid therein, oppositely movable ring and block elements cooperating'with said die, means rigid with said ring and disposed in" the liquid, means rigid with said block and also. disposed in the liquid, and a movable die for urging said ring in one direction, whereby to move said block in the opposite direction. a

9. In a sheet metal press, the combination of a fixed die having an outer band, a liquid container, a movable ring disposed interiorly of said band, elongate means rigid at one of 7 its ends withsaid ring and passing through the wall of said container, said means having its opposite end disposed in the liquid, ablock movably disposed within the hoop of said ring, a plunger rigid at one of its ends with said block and also passing through the wall of said container, said plunger havingits'opposite end disposed in the liquid, and a movable die for urging said ring-in'one direction, whereby said plunger may be effective to move said block in the opposite direction. 7 w

10. In a sheet metal press comprising a liquid container, a fixed die, movable ring and block elements cooperating with said die, said ring having rigid therewith plungers which are terminally disposed in the liquid, a plunger rigid with said block and also terminally disposed in the liquid, a movable die for urging said ring in one direction so as to move the last mentioned plunger with its block in the opposite direction,a head on the terminal ofthe last mentioned plunger, and spring means cooperating with said head and the inner surface of said container whereby to return said block to the original position. 7

' 11. In a sheet metal press, the combination of a liquid container, movable ring and block elements, plungers rigid at one of their respective ends with said elements .and having their opposite ends disposed in'the liquid, and a movable die for urging said ring in one direction whereby to move said block in the opposite direction.

12. In a sheet metal press, the combination of a table, a liquid container, cooperating movable drawring and block elements disposed above said table for receiving a sheet, plungers passing through said table and the Wall of said container and havingtheir respective top ends rigid With'said ring and said block, said plungers having their oppo-' site ends disposed in the liquid, and a movable die for urging said ring in one direction, whereby to move said block in the opposite direction for pressing the sheet.

13. In a sheet metal press, the combination of a table, a closed liquid container, cooperating drawring and block elements disposed above said table, plungers passing through said table and the Wall of saidcontainer, and having their top ends rigid with said drawring, said plungers having their opposite ends disposed in the liquid; a second plunger having its top end rigid With said block and, passing through said table and said Wall, having its bottom end also disposed in the liquid,

' a head on the last mentioned end, a reciprocable die for urging said drawring in one direction whereby, responsive to pressure in the liquid, to move the second -mentioned plunger With its block in the opposite direction, and spring means disposed between said head and the inner face of said Wall for returning said block to the original position during return movement of the reciprocable die.

In testimony whereof I have hereunto set my hand.

CHARLES JOSEPH RHODES. 

